Centralization of hardcoded IDs
First step is the creation of a top level class 'base/src/org.compiere.model.HardCodedIDs.java' which will list all centralized ID through code.
The second step will be to store those IDs into database (AD_SysConfig or new table)
Its not a good idea to use interfaces to do this. http://docs.oracle.com/javase/1.5.0/docs/guide/language/static-import.html
I have changed all the effected classes to use static imports instead:
Pull request #11 created (Display Types), next to today meeting